The present invention generally relates to ordnance having stowable fins, and, more particularly, to a missile having a deployment mechanism for deploying the fins.
Many types of ordnance utilize two or more protruding surfaces to affect the fluid flow around the ordnance, thereby facilitating control of its trajectory toward a target. Exemplary types of such ordnance include missiles, rockets, bombs, torpedoes and the like.
For example, missiles generally have an approximately cylindrical body, with at least two aerodynamic surfaces or fins that extend outwardly from the sides of the missile body to affect the aerodynamic characteristics of the missile in flight. The fins typically have an airfoil shape that is oriented edge-on or slightly inclined relative to the airflow when the missile is flying in a straight line. These fins may be, for example, static (fixed) or dynamic (selectively movable, i.e., controllable). Fixed fins generally are used to stabilize the missile during flight and do not move once fully deployed. Controllable fins (control fins) are used to control or steer the missile by selectively varying the attitude of the fins relative to the airflow under the direction of the missile""s control system.
In many cases, the fins are stowed in a position adjacent the outside surface of or within the missile body during storage and mounting on a vehicle prior to use. In some cases, the missile is stored in a tube, canister or other protective casing, and the protective casing also may serve as a launch tube. The fins are stowed to reduce the effective diameter of the missile, permitting more missiles to be stored and/or transported in a limited space. It also reduces the likelihood of damage to the fins during storage and handling. Additionally, it allows for the maximum use of the internal space of the missile for electronic components and warheads.
The fins are extended from the stowed position shortly after deployment of the missile, either during mounting or launch of the missile. Various relatively complex deployment mechanisms have been developed to permit the fins to be stowed, deployed and locked into place. Control fins may further be moved (usually only rotated) by an actuator system once the control fins are deployed.
The mechanisms presently used to deploy the fins tend to be relatively heavy, complex and expensive to design, build and maintain. Moreover, some mechanisms occupy a relatively large volume within the missile, a significant disadvantage because of the limited space within the missile.
There is a need for a simple and reliable device to support, deploy and lock stowable ordnance fins into a deployed configuration. The present invention provides a deployment mechanism for deploying stowable fins that meets this need and provides further advantages in cost, weight and space savings.
More particularly, the present invention provides a missile with the deployment mechanism that automatically deploys a fin from a stowed orientation to a deployed orientation as soon as the fin is released. The deployment mechanism includes a spring that provides a biasing force that urges the fin to move quickly, simply and reliably from the stowed orientation to the deployed orientation. The deployment mechanism also includes one or more cam slots or other means for guiding the fin from the stowed orientation to the deployed orientation.
An exemplary deployment mechanism for the missile includes a tubular cam body that can be mounted in a cylindrical cavity in the missile body. A drive pin is connected to the cam body through the spring which biases the drive pin to the deployed orientation. The fin is connected to a cam pin that extends into cam slots in the cam body to guide the fin as it is deployed. The cam pin also interconnects the fin and the drive pin. The drive pin and the spring thus cooperate to move the fin from the stowed orientation to the deployed orientation, while the cam pin and the cam slots guide the fin as it is deployed. The cam slots may also rotate the fin as it is deployed and/or lock the fin in place. Such a deployment mechanism can be used with either a fixed fin or a dynamic control fin, in any type of ordnance having stowable fins, including the missile described herein. To simplify the description, reference herein is specifically directed to missiles, but such reference includes other types of ordnance where the description would be applicable.
More particularly, one aspect of the invention relates to a deployment mechanism for a missile having at least one aerodynamic fin. The deployment mechanism comprises a spring mountable in a missile for deploying the at least one fin. The deployment mechanism is operable to move the at least one fin from a stowed orientation to a deployed orientation that is different from the stowed orientation.
Another aspect of the invention relates to the deployment mechanism further including a tubular cam having at least one cam slot and a cam pin connected to the at least one fin. The spring is connected to the cam pin to urge the cam pin to a deployed configuration. The deployed configuration includes the at least one fin in the deployed orientation. The cam pin is movable along and guided by the at least one cam slot to pivot the at least one fin and to rotate the at least one fin from the stowed orientation to the deployed orientation.
To the accomplishment of the foregoing and related ends, the invention provides the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.